From the prior art, valve devices are known, in which a valve space is sealed against a valve drive by means of a sealing body made of an elastic material. To selectively cover or clear a valve seat disposed in the valve space, a two-armed actuating lever is provided, which extends through the sealing body and whose first arm is actuated by the valve drive. The second arm of the actuating lever is inserted in a pocket molded on the sealing body, which also forms the closing body. The sealing body usually is a membrane, which is clamped on its peripheral edge and in its center has the pocket protruding into the valve space. During a swivel movement of the actuating lever, the membrane is subjected to a high load, as it is alternately stretched and compressed in the region around the pocket.